Hi Alexandre,
That’s a neat idea, though I’m afraid that neither The Events Calendar nor Event Tickets have a feature to generate certificates.
Events Calendar PRO does have a feature that allows you to create custom fields for events. You could create a PDF certificate in advance, upload it, then add it to the custom field and modify the event template so that only logged in users who have completed a course can view the custom field. It takes a little bit of custom work, but that might be a way to work around it.
Does this help answer your question? Please let me know.
Cheers,
Geoff